MachineFunction.cpp revision 1d8f83d0a00e912c55ec0974eba6122666cc6fa1 
1//===-- MachineFunction.cpp -----------------------------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// Collect native machine code information for a function.  This allows
11// target-specific information about the generated code to be stored with each
12// function.
13//
14//===----------------------------------------------------------------------===//
15
16#include "llvm/DerivedTypes.h"
17#include "llvm/Function.h"
18#include "llvm/Instructions.h"
19#include "llvm/Config/config.h"
20#include "llvm/CodeGen/MachineConstantPool.h"
21#include "llvm/CodeGen/MachineFunction.h"
22#include "llvm/CodeGen/MachineFunctionPass.h"
23#include "llvm/CodeGen/MachineFrameInfo.h"
24#include "llvm/CodeGen/MachineInstr.h"
25#include "llvm/CodeGen/MachineJumpTableInfo.h"
26#include "llvm/CodeGen/MachineRegisterInfo.h"
27#include "llvm/CodeGen/Passes.h"
28#include "llvm/MC/MCAsmInfo.h"
29#include "llvm/MC/MCContext.h"
30#include "llvm/Analysis/DebugInfo.h"
31#include "llvm/Support/Debug.h"
32#include "llvm/Target/TargetData.h"
33#include "llvm/Target/TargetLowering.h"
34#include "llvm/Target/TargetMachine.h"
35#include "llvm/Target/TargetFrameInfo.h"
36#include "llvm/ADT/SmallString.h"
37#include "llvm/ADT/STLExtras.h"
38#include "llvm/Support/GraphWriter.h"
39#include "llvm/Support/raw_ostream.h"
40using namespace llvm;
41
42namespace {
43  struct Printer : public MachineFunctionPass {
44    static char ID;
45
46    raw_ostream &OS;
47    const std::string Banner;
48
49    Printer(raw_ostream &os, const std::string &banner)
50      : MachineFunctionPass(&ID), OS(os), Banner(banner) {}
51
52    const char *getPassName() const { return "MachineFunction Printer"; }
53
54    virtual void getAnalysisUsage(AnalysisUsage &AU) const {
55      AU.setPreservesAll();
56      MachineFunctionPass::getAnalysisUsage(AU);
57    }
58
59    bool runOnMachineFunction(MachineFunction &MF) {
60      OS << "# " << Banner << ":\n";
61      MF.print(OS);
62      return false;
63    }
64  };
65  char Printer::ID = 0;
66}
67
68/// Returns a newly-created MachineFunction Printer pass. The default banner is
69/// empty.
70///
71FunctionPass *llvm::createMachineFunctionPrinterPass(raw_ostream &OS,
72                                                     const std::string &Banner){
73  return new Printer(OS, Banner);
74}
75
76//===----------------------------------------------------------------------===//
77// MachineFunction implementation
78//===----------------------------------------------------------------------===//
79
80// Out of line virtual method.
81MachineFunctionInfo::~MachineFunctionInfo() {}
82
83void ilist_traits<MachineBasicBlock>::deleteNode(MachineBasicBlock *MBB) {
84  MBB->getParent()->DeleteMachineBasicBlock(MBB);
85}
86
87MachineFunction::MachineFunction(Function *F, const TargetMachine &TM,
88                                 unsigned FunctionNum, MCContext &ctx)
89  : Fn(F), Target(TM), Ctx(ctx) {
90  if (TM.getRegisterInfo())
91    RegInfo = new (Allocator) MachineRegisterInfo(*TM.getRegisterInfo());
92  else
93    RegInfo = 0;
94  MFInfo = 0;
95  FrameInfo = new (Allocator) MachineFrameInfo(*TM.getFrameInfo());
96  if (Fn->hasFnAttr(Attribute::StackAlignment))
97    FrameInfo->setMaxAlignment(Attribute::getStackAlignmentFromAttrs(
98        Fn->getAttributes().getFnAttributes()));
99  ConstantPool = new (Allocator) MachineConstantPool(TM.getTargetData());
100  Alignment = TM.getTargetLowering()->getFunctionAlignment(F);
101  FunctionNumber = FunctionNum;
102  JumpTableInfo = 0;
103}
104
105MachineFunction::~MachineFunction() {
106  BasicBlocks.clear();
107  InstructionRecycler.clear(Allocator);
108  BasicBlockRecycler.clear(Allocator);
109  if (RegInfo) {
110    RegInfo->~MachineRegisterInfo();
111    Allocator.Deallocate(RegInfo);
112  }
113  if (MFInfo) {
114    MFInfo->~MachineFunctionInfo();
115    Allocator.Deallocate(MFInfo);
116  }
117  FrameInfo->~MachineFrameInfo();         Allocator.Deallocate(FrameInfo);
118  ConstantPool->~MachineConstantPool();   Allocator.Deallocate(ConstantPool);
119
120  if (JumpTableInfo) {
121    JumpTableInfo->~MachineJumpTableInfo();
122    Allocator.Deallocate(JumpTableInfo);
123  }
124}
125
126/// getOrCreateJumpTableInfo - Get the JumpTableInfo for this function, if it
127/// does already exist, allocate one.
128MachineJumpTableInfo *MachineFunction::
129getOrCreateJumpTableInfo(unsigned EntryKind) {
130  if (JumpTableInfo) return JumpTableInfo;
131
132  JumpTableInfo = new (Allocator)
133    MachineJumpTableInfo((MachineJumpTableInfo::JTEntryKind)EntryKind);
134  return JumpTableInfo;
135}
136
137/// RenumberBlocks - This discards all of the MachineBasicBlock numbers and
138/// recomputes them.  This guarantees that the MBB numbers are sequential,
139/// dense, and match the ordering of the blocks within the function.  If a
140/// specific MachineBasicBlock is specified, only that block and those after
141/// it are renumbered.
142void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) {
143  if (empty()) { MBBNumbering.clear(); return; }
144  MachineFunction::iterator MBBI, E = end();
145  if (MBB == 0)
146    MBBI = begin();
147  else
148    MBBI = MBB;
149
150  // Figure out the block number this should have.
151  unsigned BlockNo = 0;
152  if (MBBI != begin())
153    BlockNo = prior(MBBI)->getNumber()+1;
154
155  for (; MBBI != E; ++MBBI, ++BlockNo) {
156    if (MBBI->getNumber() != (int)BlockNo) {
157      // Remove use of the old number.
158      if (MBBI->getNumber() != -1) {
159        assert(MBBNumbering[MBBI->getNumber()] == &*MBBI &&
160               "MBB number mismatch!");
161        MBBNumbering[MBBI->getNumber()] = 0;
162      }
163
164      // If BlockNo is already taken, set that block's number to -1.
165      if (MBBNumbering[BlockNo])
166        MBBNumbering[BlockNo]->setNumber(-1);
167
168      MBBNumbering[BlockNo] = MBBI;
169      MBBI->setNumber(BlockNo);
170    }
171  }
172
173  // Okay, all the blocks are renumbered.  If we have compactified the block
174  // numbering, shrink MBBNumbering now.
175  assert(BlockNo <= MBBNumbering.size() && "Mismatch!");
176  MBBNumbering.resize(BlockNo);
177}
178
179/// CreateMachineInstr - Allocate a new MachineInstr. Use this instead
180/// of `new MachineInstr'.
181///
182MachineInstr *
183MachineFunction::CreateMachineInstr(const TargetInstrDesc &TID,
184                                    DebugLoc DL, bool NoImp) {
185  return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
186    MachineInstr(TID, DL, NoImp);
187}
188
189/// CloneMachineInstr - Create a new MachineInstr which is a copy of the
190/// 'Orig' instruction, identical in all ways except the instruction
191/// has no parent, prev, or next.
192///
193MachineInstr *
194MachineFunction::CloneMachineInstr(const MachineInstr *Orig) {
195  return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
196             MachineInstr(*this, *Orig);
197}
198
199/// DeleteMachineInstr - Delete the given MachineInstr.
200///
201void
202MachineFunction::DeleteMachineInstr(MachineInstr *MI) {
203  MI->~MachineInstr();
204  InstructionRecycler.Deallocate(Allocator, MI);
205}
206
207/// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this
208/// instead of `new MachineBasicBlock'.
209///
210MachineBasicBlock *
211MachineFunction::CreateMachineBasicBlock(const BasicBlock *bb) {
212  return new (BasicBlockRecycler.Allocate<MachineBasicBlock>(Allocator))
213             MachineBasicBlock(*this, bb);
214}
215
216/// DeleteMachineBasicBlock - Delete the given MachineBasicBlock.
217///
218void
219MachineFunction::DeleteMachineBasicBlock(MachineBasicBlock *MBB) {
220  assert(MBB->getParent() == this && "MBB parent mismatch!");
221  MBB->~MachineBasicBlock();
222  BasicBlockRecycler.Deallocate(Allocator, MBB);
223}
224
225MachineMemOperand *
226MachineFunction::getMachineMemOperand(const Value *v, unsigned f,
227                                      int64_t o, uint64_t s,
228                                      unsigned base_alignment) {
229  return new (Allocator) MachineMemOperand(v, f, o, s, base_alignment);
230}
231
232MachineMemOperand *
233MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO,
234                                      int64_t Offset, uint64_t Size) {
235  return new (Allocator)
236             MachineMemOperand(MMO->getValue(), MMO->getFlags(),
237                               int64_t(uint64_t(MMO->getOffset()) +
238                                       uint64_t(Offset)),
239                               Size, MMO->getBaseAlignment());
240}
241
242MachineInstr::mmo_iterator
243MachineFunction::allocateMemRefsArray(unsigned long Num) {
244  return Allocator.Allocate<MachineMemOperand *>(Num);
245}
246
247std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator>
248MachineFunction::extractLoadMemRefs(MachineInstr::mmo_iterator Begin,
249                                    MachineInstr::mmo_iterator End) {
250  // Count the number of load mem refs.
251  unsigned Num = 0;
252  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I)
253    if ((*I)->isLoad())
254      ++Num;
255
256  // Allocate a new array and populate it with the load information.
257  MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num);
258  unsigned Index = 0;
259  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) {
260    if ((*I)->isLoad()) {
261      if (!(*I)->isStore())
262        // Reuse the MMO.
263        Result[Index] = *I;
264      else {
265        // Clone the MMO and unset the store flag.
266        MachineMemOperand *JustLoad =
267          getMachineMemOperand((*I)->getValue(),
268                               (*I)->getFlags() & ~MachineMemOperand::MOStore,
269                               (*I)->getOffset(), (*I)->getSize(),
270                               (*I)->getBaseAlignment());
271        Result[Index] = JustLoad;
272      }
273      ++Index;
274    }
275  }
276  return std::make_pair(Result, Result + Num);
277}
278
279std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator>
280MachineFunction::extractStoreMemRefs(MachineInstr::mmo_iterator Begin,
281                                     MachineInstr::mmo_iterator End) {
282  // Count the number of load mem refs.
283  unsigned Num = 0;
284  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I)
285    if ((*I)->isStore())
286      ++Num;
287
288  // Allocate a new array and populate it with the store information.
289  MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num);
290  unsigned Index = 0;
291  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) {
292    if ((*I)->isStore()) {
293      if (!(*I)->isLoad())
294        // Reuse the MMO.
295        Result[Index] = *I;
296      else {
297        // Clone the MMO and unset the load flag.
298        MachineMemOperand *JustStore =
299          getMachineMemOperand((*I)->getValue(),
300                               (*I)->getFlags() & ~MachineMemOperand::MOLoad,
301                               (*I)->getOffset(), (*I)->getSize(),
302                               (*I)->getBaseAlignment());
303        Result[Index] = JustStore;
304      }
305      ++Index;
306    }
307  }
308  return std::make_pair(Result, Result + Num);
309}
310
311void MachineFunction::dump() const {
312  print(dbgs());
313}
314
315void MachineFunction::print(raw_ostream &OS) const {
316  OS << "# Machine code for function " << Fn->getName() << ":\n";
317
318  // Print Frame Information
319  FrameInfo->print(*this, OS);
320
321  // Print JumpTable Information
322  if (JumpTableInfo)
323    JumpTableInfo->print(OS);
324
325  // Print Constant Pool
326  ConstantPool->print(OS);
327
328  const TargetRegisterInfo *TRI = getTarget().getRegisterInfo();
329
330  if (RegInfo && !RegInfo->livein_empty()) {
331    OS << "Function Live Ins: ";
332    for (MachineRegisterInfo::livein_iterator
333         I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) {
334      if (TRI)
335        OS << "%" << TRI->getName(I->first);
336      else
337        OS << " %physreg" << I->first;
338
339      if (I->second)
340        OS << " in reg%" << I->second;
341
342      if (llvm::next(I) != E)
343        OS << ", ";
344    }
345    OS << '\n';
346  }
347  if (RegInfo && !RegInfo->liveout_empty()) {
348    OS << "Function Live Outs: ";
349    for (MachineRegisterInfo::liveout_iterator
350         I = RegInfo->liveout_begin(), E = RegInfo->liveout_end(); I != E; ++I){
351      if (TRI)
352        OS << '%' << TRI->getName(*I);
353      else
354        OS << "%physreg" << *I;
355
356      if (llvm::next(I) != E)
357        OS << " ";
358    }
359    OS << '\n';
360  }
361
362  for (const_iterator BB = begin(), E = end(); BB != E; ++BB) {
363    OS << '\n';
364    BB->print(OS);
365  }
366
367  OS << "\n# End machine code for function " << Fn->getName() << ".\n\n";
368}
369
370namespace llvm {
371  template<>
372  struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits {
373
374  DOTGraphTraits (bool isSimple=false) : DefaultDOTGraphTraits(isSimple) {}
375
376    static std::string getGraphName(const MachineFunction *F) {
377      return "CFG for '" + F->getFunction()->getNameStr() + "' function";
378    }
379
380    std::string getNodeLabel(const MachineBasicBlock *Node,
381                             const MachineFunction *Graph) {
382      if (isSimple () && Node->getBasicBlock() &&
383          !Node->getBasicBlock()->getName().empty())
384        return Node->getBasicBlock()->getNameStr() + ":";
385
386      std::string OutStr;
387      {
388        raw_string_ostream OSS(OutStr);
389
390        if (isSimple())
391          OSS << Node->getNumber() << ':';
392        else
393          Node->print(OSS);
394      }
395
396      if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
397
398      // Process string output to make it nicer...
399      for (unsigned i = 0; i != OutStr.length(); ++i)
400        if (OutStr[i] == '\n') {                            // Left justify
401          OutStr[i] = '\\';
402          OutStr.insert(OutStr.begin()+i+1, 'l');
403        }
404      return OutStr;
405    }
406  };
407}
408
409void MachineFunction::viewCFG() const
410{
411#ifndef NDEBUG
412  ViewGraph(this, "mf" + getFunction()->getNameStr());
413#else
414  errs() << "SelectionDAG::viewGraph is only available in debug builds on "
415         << "systems with Graphviz or gv!\n";
416#endif // NDEBUG
417}
418
419void MachineFunction::viewCFGOnly() const
420{
421#ifndef NDEBUG
422  ViewGraph(this, "mf" + getFunction()->getNameStr(), true);
423#else
424  errs() << "SelectionDAG::viewGraph is only available in debug builds on "
425         << "systems with Graphviz or gv!\n";
426#endif // NDEBUG
427}
428
429/// addLiveIn - Add the specified physical register as a live-in value and
430/// create a corresponding virtual register for it.
431unsigned MachineFunction::addLiveIn(unsigned PReg,
432                                    const TargetRegisterClass *RC) {
433  assert(RC->contains(PReg) && "Not the correct regclass!");
434  unsigned VReg = getRegInfo().createVirtualRegister(RC);
435  getRegInfo().addLiveIn(PReg, VReg);
436  return VReg;
437}
438
439/// getDILocation - Get the DILocation for a given DebugLoc object.
440DILocation MachineFunction::getDILocation(DebugLoc DL) const {
441  unsigned Idx = DL.getIndex();
442  assert(Idx < DebugLocInfo.DebugLocations.size() &&
443         "Invalid index into debug locations!");
444  return DILocation(DebugLocInfo.DebugLocations[Idx]);
445}
446
447
448/// getJTISymbol - Return the MCSymbol for the specified non-empty jump table.
449/// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a
450/// normal 'L' label is returned.
451MCSymbol *MachineFunction::getJTISymbol(unsigned JTI, MCContext &Ctx,
452                                        bool isLinkerPrivate) const {
453  assert(JumpTableInfo && "No jump tables");
454
455  assert(JTI < JumpTableInfo->getJumpTables().size() && "Invalid JTI!");
456  const MCAsmInfo &MAI = *getTarget().getMCAsmInfo();
457
458  const char *Prefix = isLinkerPrivate ? MAI.getLinkerPrivateGlobalPrefix() :
459                                         MAI.getPrivateGlobalPrefix();
460  SmallString<60> Name;
461  raw_svector_ostream(Name)
462    << Prefix << "JTI" << getFunctionNumber() << '_' << JTI;
463  return Ctx.GetOrCreateSymbol(Name.str());
464}
465
466
467//===----------------------------------------------------------------------===//
468//  MachineFrameInfo implementation
469//===----------------------------------------------------------------------===//
470
471/// CreateFixedObject - Create a new object at a fixed location on the stack.
472/// All fixed objects should be created before other objects are created for
473/// efficiency. By default, fixed objects are immutable. This returns an
474/// index with a negative value.
475///
476int MachineFrameInfo::CreateFixedObject(uint64_t Size, int64_t SPOffset,
477                                        bool Immutable, bool isSS) {
478  assert(Size != 0 && "Cannot allocate zero size fixed stack objects!");
479  Objects.insert(Objects.begin(), StackObject(Size, 1, SPOffset, Immutable,
480                                              isSS));
481  return -++NumFixedObjects;
482}
483
484
485BitVector
486MachineFrameInfo::getPristineRegs(const MachineBasicBlock *MBB) const {
487  assert(MBB && "MBB must be valid");
488  const MachineFunction *MF = MBB->getParent();
489  assert(MF && "MBB must be part of a MachineFunction");
490  const TargetMachine &TM = MF->getTarget();
491  const TargetRegisterInfo *TRI = TM.getRegisterInfo();
492  BitVector BV(TRI->getNumRegs());
493
494  // Before CSI is calculated, no registers are considered pristine. They can be
495  // freely used and PEI will make sure they are saved.
496  if (!isCalleeSavedInfoValid())
497    return BV;
498
499  for (const unsigned *CSR = TRI->getCalleeSavedRegs(MF); CSR && *CSR; ++CSR)
500    BV.set(*CSR);
501
502  // The entry MBB always has all CSRs pristine.
503  if (MBB == &MF->front())
504    return BV;
505
506  // On other MBBs the saved CSRs are not pristine.
507  const std::vector<CalleeSavedInfo> &CSI = getCalleeSavedInfo();
508  for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(),
509         E = CSI.end(); I != E; ++I)
510    BV.reset(I->getReg());
511
512  return BV;
513}
514
515
516void MachineFrameInfo::print(const MachineFunction &MF, raw_ostream &OS) const{
517  if (Objects.empty()) return;
518
519  const TargetFrameInfo *FI = MF.getTarget().getFrameInfo();
520  int ValOffset = (FI ? FI->getOffsetOfLocalArea() : 0);
521
522  OS << "Frame Objects:\n";
523
524  for (unsigned i = 0, e = Objects.size(); i != e; ++i) {
525    const StackObject &SO = Objects[i];
526    OS << "  fi#" << (int)(i-NumFixedObjects) << ": ";
527    if (SO.Size == ~0ULL) {
528      OS << "dead\n";
529      continue;
530    }
531    if (SO.Size == 0)
532      OS << "variable sized";
533    else
534      OS << "size=" << SO.Size;
535    OS << ", align=" << SO.Alignment;
536
537    if (i < NumFixedObjects)
538      OS << ", fixed";
539    if (i < NumFixedObjects || SO.SPOffset != -1) {
540      int64_t Off = SO.SPOffset - ValOffset;
541      OS << ", at location [SP";
542      if (Off > 0)
543        OS << "+" << Off;
544      else if (Off < 0)
545        OS << Off;
546      OS << "]";
547    }
548    OS << "\n";
549  }
550}
551
552void MachineFrameInfo::dump(const MachineFunction &MF) const {
553  print(MF, dbgs());
554}
555
556//===----------------------------------------------------------------------===//
557//  MachineJumpTableInfo implementation
558//===----------------------------------------------------------------------===//
559
560/// getEntrySize - Return the size of each entry in the jump table.
561unsigned MachineJumpTableInfo::getEntrySize(const TargetData &TD) const {
562  // The size of a jump table entry is 4 bytes unless the entry is just the
563  // address of a block, in which case it is the pointer size.
564  switch (getEntryKind()) {
565  case MachineJumpTableInfo::EK_BlockAddress:
566    return TD.getPointerSize();
567  case MachineJumpTableInfo::EK_GPRel32BlockAddress:
568  case MachineJumpTableInfo::EK_LabelDifference32:
569  case MachineJumpTableInfo::EK_Custom32:
570    return 4;
571  case MachineJumpTableInfo::EK_Inline:
572    return 0;
573  }
574  assert(0 && "Unknown jump table encoding!");
575  return ~0;
576}
577
578/// getEntryAlignment - Return the alignment of each entry in the jump table.
579unsigned MachineJumpTableInfo::getEntryAlignment(const TargetData &TD) const {
580  // The alignment of a jump table entry is the alignment of int32 unless the
581  // entry is just the address of a block, in which case it is the pointer
582  // alignment.
583  switch (getEntryKind()) {
584  case MachineJumpTableInfo::EK_BlockAddress:
585    return TD.getPointerABIAlignment();
586  case MachineJumpTableInfo::EK_GPRel32BlockAddress:
587  case MachineJumpTableInfo::EK_LabelDifference32:
588  case MachineJumpTableInfo::EK_Custom32:
589    return TD.getABIIntegerTypeAlignment(32);
590  case MachineJumpTableInfo::EK_Inline:
591    return 1;
592  }
593  assert(0 && "Unknown jump table encoding!");
594  return ~0;
595}
596
597/// createJumpTableIndex - Create a new jump table entry in the jump table info.
598///
599unsigned MachineJumpTableInfo::createJumpTableIndex(
600                               const std::vector<MachineBasicBlock*> &DestBBs) {
601  assert(!DestBBs.empty() && "Cannot create an empty jump table!");
602  JumpTables.push_back(MachineJumpTableEntry(DestBBs));
603  return JumpTables.size()-1;
604}
605
606/// ReplaceMBBInJumpTables - If Old is the target of any jump tables, update
607/// the jump tables to branch to New instead.
608bool MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old,
609                                                  MachineBasicBlock *New) {
610  assert(Old != New && "Not making a change?");
611  bool MadeChange = false;
612  for (size_t i = 0, e = JumpTables.size(); i != e; ++i)
613    ReplaceMBBInJumpTable(i, Old, New);
614  return MadeChange;
615}
616
617/// ReplaceMBBInJumpTable - If Old is a target of the jump tables, update
618/// the jump table to branch to New instead.
619bool MachineJumpTableInfo::ReplaceMBBInJumpTable(unsigned Idx,
620                                                 MachineBasicBlock *Old,
621                                                 MachineBasicBlock *New) {
622  assert(Old != New && "Not making a change?");
623  bool MadeChange = false;
624  MachineJumpTableEntry &JTE = JumpTables[Idx];
625  for (size_t j = 0, e = JTE.MBBs.size(); j != e; ++j)
626    if (JTE.MBBs[j] == Old) {
627      JTE.MBBs[j] = New;
628      MadeChange = true;
629    }
630  return MadeChange;
631}
632
633void MachineJumpTableInfo::print(raw_ostream &OS) const {
634  if (JumpTables.empty()) return;
635
636  OS << "Jump Tables:\n";
637
638  for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) {
639    OS << "  jt#" << i << ": ";
640    for (unsigned j = 0, f = JumpTables[i].MBBs.size(); j != f; ++j)
641      OS << " BB#" << JumpTables[i].MBBs[j]->getNumber();
642  }
643
644  OS << '\n';
645}
646
647void MachineJumpTableInfo::dump() const { print(dbgs()); }
648
649
650//===----------------------------------------------------------------------===//
651//  MachineConstantPool implementation
652//===----------------------------------------------------------------------===//
653
654const Type *MachineConstantPoolEntry::getType() const {
655  if (isMachineConstantPoolEntry())
656    return Val.MachineCPVal->getType();
657  return Val.ConstVal->getType();
658}
659
660
661unsigned MachineConstantPoolEntry::getRelocationInfo() const {
662  if (isMachineConstantPoolEntry())
663    return Val.MachineCPVal->getRelocationInfo();
664  return Val.ConstVal->getRelocationInfo();
665}
666
667MachineConstantPool::~MachineConstantPool() {
668  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
669    if (Constants[i].isMachineConstantPoolEntry())
670      delete Constants[i].Val.MachineCPVal;
671}
672
673/// CanShareConstantPoolEntry - Test whether the given two constants
674/// can be allocated the same constant pool entry.
675static bool CanShareConstantPoolEntry(Constant *A, Constant *B,
676                                      const TargetData *TD) {
677  // Handle the trivial case quickly.
678  if (A == B) return true;
679
680  // If they have the same type but weren't the same constant, quickly
681  // reject them.
682  if (A->getType() == B->getType()) return false;
683
684  // For now, only support constants with the same size.
685  if (TD->getTypeStoreSize(A->getType()) != TD->getTypeStoreSize(B->getType()))
686    return false;
687
688  // If a floating-point value and an integer value have the same encoding,
689  // they can share a constant-pool entry.
690  if (ConstantFP *AFP = dyn_cast<ConstantFP>(A))
691    if (ConstantInt *BI = dyn_cast<ConstantInt>(B))
692      return AFP->getValueAPF().bitcastToAPInt() == BI->getValue();
693  if (ConstantFP *BFP = dyn_cast<ConstantFP>(B))
694    if (ConstantInt *AI = dyn_cast<ConstantInt>(A))
695      return BFP->getValueAPF().bitcastToAPInt() == AI->getValue();
696
697  // Two vectors can share an entry if each pair of corresponding
698  // elements could.
699  if (ConstantVector *AV = dyn_cast<ConstantVector>(A))
700    if (ConstantVector *BV = dyn_cast<ConstantVector>(B)) {
701      if (AV->getType()->getNumElements() != BV->getType()->getNumElements())
702        return false;
703      for (unsigned i = 0, e = AV->getType()->getNumElements(); i != e; ++i)
704        if (!CanShareConstantPoolEntry(AV->getOperand(i),
705                                       BV->getOperand(i), TD))
706          return false;
707      return true;
708    }
709
710  // TODO: Handle other cases.
711
712  return false;
713}
714
715/// getConstantPoolIndex - Create a new entry in the constant pool or return
716/// an existing one.  User must specify the log2 of the minimum required
717/// alignment for the object.
718///
719unsigned MachineConstantPool::getConstantPoolIndex(Constant *C,
720                                                   unsigned Alignment) {
721  assert(Alignment && "Alignment must be specified!");
722  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
723
724  // Check to see if we already have this constant.
725  //
726  // FIXME, this could be made much more efficient for large constant pools.
727  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
728    if (!Constants[i].isMachineConstantPoolEntry() &&
729        CanShareConstantPoolEntry(Constants[i].Val.ConstVal, C, TD)) {
730      if ((unsigned)Constants[i].getAlignment() < Alignment)
731        Constants[i].Alignment = Alignment;
732      return i;
733    }
734
735  Constants.push_back(MachineConstantPoolEntry(C, Alignment));
736  return Constants.size()-1;
737}
738
739unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V,
740                                                   unsigned Alignment) {
741  assert(Alignment && "Alignment must be specified!");
742  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
743
744  // Check to see if we already have this constant.
745  //
746  // FIXME, this could be made much more efficient for large constant pools.
747  int Idx = V->getExistingMachineCPValue(this, Alignment);
748  if (Idx != -1)
749    return (unsigned)Idx;
750
751  Constants.push_back(MachineConstantPoolEntry(V, Alignment));
752  return Constants.size()-1;
753}
754
755void MachineConstantPool::print(raw_ostream &OS) const {
756  if (Constants.empty()) return;
757
758  OS << "Constant Pool:\n";
759  for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
760    OS << "  cp#" << i << ": ";
761    if (Constants[i].isMachineConstantPoolEntry())
762      Constants[i].Val.MachineCPVal->print(OS);
763    else
764      OS << *(Value*)Constants[i].Val.ConstVal;
765    OS << ", align=" << Constants[i].getAlignment();
766    OS << "\n";
767  }
768}
769
770void MachineConstantPool::dump() const { print(dbgs()); }
771